/*
 * Copyright (c) 2019, 2019, Oracle and/or its affiliates.
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are
 * permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this list of
 * conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice, this list of
 * conditions and the following disclaimer in the documentation and/or other materials provided
 * with the distribution.
 *
 * 3. Neither the name of the copyright holder nor the names of its contributors may be used to
 * endorse or promote products derived from this software without specific prior written
 * permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS
 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#include <signal.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>

void old_style_handler_old(int signo) {
}

void old_style_handler_new(int signo) {
}

int main(void) {
  struct sigaction sa = { 0 };
  sa.sa_handler = old_style_handler_old;
  sigemptyset(&sa.sa_mask);
  errno = 0;
  if (sigaction(SIGINT, &sa, NULL) != 0) {
    if (errno != EINVAL) {
      return 1;
    }
    return 2;
  }

  sa.sa_handler = old_style_handler_new;
  struct sigaction osa = { 0 };
  errno = 0;
  if (sigaction(SIGINT, &sa, &osa) != 0) {
    if (errno != EINVAL) {
      return 3;
    }
    return 4;
  }
  if (osa.sa_handler != old_style_handler_old) {
    return 5;
  }

  /* unset handler */
  sa.sa_handler = NULL;
  errno = 0;
  if (sigaction(SIGINT, &sa, &osa) != 0) {
    if (errno != EINVAL) {
      return 6;
    }
    return 7;
  }
  if (osa.sa_handler != old_style_handler_new) {
    return 8;
  }

  return 0;
}
